In the field of computing, stylus-based input is growing more prevalent with the increasingly widespread use of computing devices such as personal digital assistants (PDAs), tablet computers, laptop computers, and the like. The input devices used to detect contact and position by a stylus shall hereinafter be referred to as digitizers. A digitizer may be attached to or otherwise integrated with the display surface of a display device. The display device may further be separate from or integral with a computing device. For example, a tablet computer typically has an integral display device with a digitizer. Alternatively, a digitizer may take the form of an external peripheral such as a digitizing tablet. Some types of digitizers are able to translate a stylus contact with the digitizer into a two-dimensional position that corresponds to coordinates on the display surface closest to where the tip of the stylus came into contact.
Along with position, digitizers are able to detect the amount of pressure exerted by the user when making contact with a stylus. This information may be passed to the computing device in the form of a magnitude, perhaps as an eight-bit number. Typically, however, most operating systems, applications, and other software ignore this information, primarily interpreting contact pressure as a single click, regardless of magnitude. Notable exceptions include Adobe's Photoshop® and similar graphics programs, which use pressure on a digitizer tablet to simulate the varying strokes of a virtual paint brush.
It would be an enhancement for graphical interface users to take full advantage of pressure as an input throughout an operating system, applications, and/or other software. It would also be an enhancement for graphical interface users to develop faster and more accurate control of interface functions using existing hardware. Further, it would be an enhancement for graphical interface users to achieve additional intuitive functionality from existing input devices without confusing users with additional buttons or switches.